The growing demand for sheet metal calls for new high-capacity rolling mills which would guarantee high-quality products. Thin strip is produced on mills with only one drive roll in each of the working stands. This design reduces the rolling force, provides for a great amount of pass reduction, decreases thickness variations, and improves the surface finish.
There is known a roll mill stand (cf. the collection of abstracts "Oborudovanie dlya prokatnogo proizvodstva"/3Rolling Equipment"/, Metallurgicheskoe oborudovanie/Metallurgical Equipment/Series, the Publishing House of TsNIITEITyazhmash, Moscow, 1979, pp. 4-6) comprising a main roll mounted in bearings encompassed by pads, and an auxiliary roll with the strip fed into the rolls. The stand further incorporates a housing with guides. The pads and the auxiliary roll are movable on said guides. Finally, the stand includes a mechanism to control the profile and shape of the strip, which comprises a drive mechanically coupled to the housing and to at least one of the rolls. The function of this mechanism is performed by at least four hydraulic cylinders accommodated in bolsters. The rods of the cylinders are mechanically connected to the auxiliary roll.
The roll mill stand described above is disadvantageous in that the design of the mechanism to control the profile and shape of the strip accounts for a relatively great load on the housing and the bearings of the main roll. This load may be as high as 15 to 40 percent of the rolling force. It reduces the life of the bearings and necessitates putting a great amount of metal into the manufacture of the stand.
In addition, the mechanism to control the profile and shape of the strip is designed so that replacement of the main roll is quite a lengthy process, which tells on the overall efficiency of the mill.